I USE A FIT­NESS TRACKER TO MON­I­TOR MY SLEEP BUT AM NOT SURE WHAT I DO WITH THE DATA.

You’ve just hit on one of the big­gest prob­lems in the sleep-track­ing world. Ready for two more? Not all track­ers are ac­cu­rate, and they don’t all agree when it comes to stan­dard def­i­ni­tions of cer­tain terms like “deep sleep.”

But let’s as­sume your tracker is ac­cu­rate—what next? First, you’ll want to put your data in con­text by com­par­ing it with the data of other peo­ple of your gender and age. If you’re a 38-year-old fe­male, you want to know what your data looks like rel­a­tive to the av­er­age woman your age.

Next, you’ll want in­sight into im­prove­ments you can make for peak sleep per­for­mance. This would re­quire a real-time advice en­gine that would give you in­for­ma­tion based on your pre­vi­ous night’s sleep and lead you to per­son­al­ized sleep goals. The only track­ing sys­tem I’ve found that does this re­li­ably is the Sleep­score Max (sleep­score.com, $150). The com­pany also re­cently re­leased a free app that uses your smart­phone to track and an­a­lyze your sleep as well.